A Guide To Compression Dressings For Venous Ulcers

Given the relatively common incidence of venous insufficiency and the high likelihood of recurrence with venous leg ulcers, these authors offer a thorough review of the literature and share their insights on compression modalities ranging from inelastic (short stretch) bandages to intermittent pneumatic compression therapy.

Venous insufficiency affects approximately 30 percent of the population and venous leg ulcers (VLUs) comprise the majority of leg ulcers. Venous leg ulcers have a high recurrence rate and many clinicians consider compression therapy to be the gold standard in the management of venous ulcerations.

While there are a myriad of compression alternatives available on the market, there is not a one-size-fits-all answer when choosing the type of product to use. The wrong compression product can lead to complications from skin necrosis to severe ischemia.1,2 Inappropriate application and lack of consideration for the individual needs of the patient can lead to ineffective therapy and diminished quality of life. A good working knowledge of compression therapy options is essential to achieve the best outcomes.

While the exact mechanism of venous ulcer formation is still unclear, it is well recognized that the underlying pathology is related to venous insufficiency secondary to longstanding venous hypertension.3 Pathology can occur in the deep, superficial, perforator or all three venous systems.4 Causes may be structural, functional or both as in the case of a patient who develops complicating deep vein thrombosis after undergoing an ankle arthrodesis procedure.5

Researchers have shown that calf pump dysfunction and decreased ankle range of motion are significant factors in the development of venous ulceration.6-9 Ultimately, chronic tissue damage occurs, leading to development of the characteristic manifestations of chronic venous insufficiency (CVI), including edema, skin changes and ulceration.5 Healed ulcerations can have a five-year recurrence rate as high as 40 percent.10

When patients are in a supine position, pressure in the veins normally approximates 10 mmHg. When patients are standing, the pressure increases up to 80 to 100 mmHg.5 The mean hydrostatic pressure decreases to 22 mmHg during ambulation because of actions from the calf and foot pump.5 In people with chronic venous insufficiency, however, ambulatory pressures consistently exceed that of 40 mmHg. Nicolaides and co-workers noted that almost all patients with CVI who had exercising venous pressures in excess of 90 mmHg developed ulceration.11

Graduated compression therapy can reduce the vessel diameters and redirect blood centrally, reduce edema, and may also improve arterial circulation.12 Additionally, there is evidence that compression can reduce levels of destructive proteases and inflammatory cytokines that may contribute to ulcer formation and chronicity.13 A Cochrane Review by Cullum and colleagues reported that treatment of venous ulcers with compression is better than no compression, higher compression is more effective than low compression, and multi-layer bandage systems are more effective than single-layer systems.14 Despite surgical advances, compression therapy continues to be the most common conservative treatment for venous ulceration and chronic venous insufficiency.5

Pertinent Insights On Compression Products

One can divide compression products into different categories: elastic versus inelastic; short versus long stretch; high compression versus mild versus low; single- versus multi-layer; and stockings versus bandages versus pumps. The products vary in their actions and pressures, but are generally classified based on the level of compression provided at the ankle.15 Several guidelines offer recommendations for the treatment of venous insufficiency.4 In theory, the goal compression for a patient without arterial disease should approach 40 mmHg at the ankle. With decreased ankle-brachial indices, less pressure is recommended.16

To achieve a graduated compression gradient, one needs to apply a bandage at a consistent tension and the bandage should be able to retain its shape over a long period of time. The pressure exerted on a limb is directly related to the number of layers one applies, the tension of application and is inversely related to the circumference of the limb and the width of the bandage.17 In other words, the more layers and the higher the tension, the higher the pressure. The smaller the limb and the narrower the bandage, the higher the pressure.

When clinicians apply a compression bandage to a normally shaped leg, the narrower ankle, when wrapped with the same bandage at the same tension with a consistent 50 percent overlap, will have a higher sub-bandage pressure than the wider thigh. Accordingly, this provides a graduated compression and improving venous return.
Practitioner technique can also affect the sub-bandage pressure.5 Skilled instruction is recommended prior to introducing these techniques into clinical practice.

What The Research Reveals About Inelastic (Short Stretch) Bandages

Inelastic bandages, also known as short stretch bandages, have minimal stretch and can only extend up to 30 to 70 percent of their length.18 Examples of inelastic bandages are included in the table “An Overview Of Compression Products For Venous Ulcers” at left. Patients can launder and reuse many of these bandages. Inelastic bandages provide compression not so much in the bandage itself but as a firm barrier against which the calf muscle presses during ambulation, thus supporting calf pump action.16

The inelasticity offers a high working pressure (30 to 40 mmHg) during ambulation and a low resting pressure when the leg is inactive or supine.19 This property may allow safer use when the patient has a venous ulcer in combination with decreased arterial circulation.16 One small study demonstrated safe and effective venous ulcer treatment with short stretch bandaging in 24 patients with a mean ankle-brachial index (ABI) of 0.62.20 These bandages may not be the best choices for patients with inadequate calf pumps such as those with limited ankle mobility, abnormal gait patterns, paralysis, immobility, and muscle wasting diseases that result in lower extremity muscle atrophy.5,21,22

The recommended application for inelastic bandages is a spiral wrap from the base of the toes to two fingerbreadths below the patella with a 50 percent overlap, consistent tension and avoidance of wrinkles and folds.

Clinicians may employ short stretch bandages to decrease edema. However, they are unable to sustain consistent compression for prolonged periods of time.23 The inelastic characteristics of these types of bandages do not allow for contouring of the bandage to the leg circumference once the edema has decreased. This can lead to slippage and creases in the bandage that can cause skin breakdown and discomfort.24 Therefore, one may need to change inelastic bandages more frequently until edema reduction has reached a steady state.16,25

The literature suggests that short stretch bandaging is as effective as any other compression bandage at reducing edema. However, short stretch bandaging may not be as effective at healing ulcerations.26

When it comes to long-term ulcers, clinicians can teach caregivers how to apply short stretch reusable bandages.27 The bandages can be washed per manufacturer recommendations and hung to dry. Replace these bandages every few months. Typically to protect the skin, clinicians use a layer of tube gauze or stockinette over the primary wound dressing.

The inelastic or short stretch bandages have limited absorptive qualities and may not be optimal in wounds with heavy or excessive drainage. In such cases, the clinician may consider an initial treatment with an Unna boot or multilayer lower compression bandage to manage the heavy drainage, and transition to the inelastic or short stretch bandage after successful exudate management.

Unna boots are disposable inelastic bandages that have zinc or calamine paste components that may decrease pruritus, dry stasis dermatitis lesions, and help soothe discomfort. One can apply the Unna boot directly over the wound bed or over another primary wound dressing. Then the clinician would secure it with self-adherent cohesive bandaging. This allows for a greater degree of leg conformability as edema decreases. Addition of the elastic outer layer also creates a bandage with a more consistent working pressure and a higher resting pressure.23 Often, it is necessary to apply a middle layer of gauze or cast padding to absorb wound drainage.

What You Should Know About Elastic (Long Stretch) Bandages

The elastic bandages, as their name implies, have high elasticity and are able to stretch up to several times their length. They accommodate the shape of the leg and sustain high pressures during both ambulation and relaxation.5 The table “An Overview Of Compression Products For Venous Ulcers” (above) lists examples of elastic or long stretch bandages.

This bandage type is recommended for patients who are immobile, have a fixed ankle joint or an inadequate calf pump.16 They are not intended for use in patients with arterial insufficiency. Patients can also reuse and wash these bandages according to the manufacturer recommendations. Several companies make high compression elastic bandages that have rectangular or square markings along the bandage to ensure a constant tension during application. One may need to apply padding to prevent localized areas of excessively high pressure, especially over prominent tibial crests.

It is important to note that greater elasticity does not always equate to better efficacy. A bandage with too high an elasticity will provide too low a working pressure to facilitate venous flow. This is because the high elasticity will allow the bandage to flex excessively with each leg movement rather than support the calf pump. A bandage with too high an elasticity will also provide a high resting pressure that may vary along the length of the leg. This variation can hinder venous flow due to uneven pressure gradients and potentially be dangerous in the presence of arterial disease.16

Examples of this type of bandage are those physicians typically use for the management of orthopedic injuries or as surgical dressings such as ACE bandages. ACE wraps are intended for short-term use, not for the treatment of chronic venous insufficiency.

Essential Insights On Multi-Layer Bandaging

Multi-layer bandages most often have three or four layers, and are generally a combination of inelastic and elastic bandage, padding, cohesive and crepe layers. In addition to the multiple layers, a combination of spiral and figure eight wrapping techniques results in a bandage that maintains its compression gradient for extended periods of time during both activity and rest.28 Patients with poor calf pump function can benefit from the elastic components while the inelastic components provide high working pressures and can offer lower resting pressures.18 Several multi-layer kits exist that are advertised as “light.” These are two-layer bandages that researchers have shown are safe for use on patients with mild to moderate arterial insufficiency.16,29

Multi-layer kit components vary. It is wise to review the product insert prior to application. Multi-layer bandages often have higher per unit costs. However, these bandages only need weekly changes and the literature supports improved healing times with four-layer bandages rather than single or lower compression alternatives.14,30

Unfortunately, these bandages are often bulky and create difficulty with shoe wear.31 This can create resistance to and dissatisfaction with the plan of care. Additionally, several studies have shown that compression bandages may restrict ankle range of motion and gait capacity.21,31 This may place the patient at an increased fall risk and further decrease calf pump function. Despite these possible disadvantages, the European Wound Healing Society recommends multi-layer bandages as first line therapy in both mobile and immobile patients.16

Can Intermittent Pneumatic Compression Therapy Have An Impact?

A recent Cochrane Review by Nelson and colleagues concluded that intermittent pneumatic compression (IPC) may increase healing in comparison to no compression, but the studies have been small and more research is needed.32 Treatment with intermittent pneumatic compression may also shorten the duration of therapy, reduce cost and return the patient to activity sooner.33 In patients who have recalcitrant ulcers, lipodermatosclerosis and calf pump dysfunction, the addition of a sequential pneumatic compression device to compression bandages or stocking therapy may improve healing.

To qualify, it is often necessary to produce documentation of venous ulcers that are unresponsive to standard treatment for at least six months. Most insurance policies will cover the unit with the appropriate documentation. There is a degree of paperwork (including a letter of necessity) involved. Manufacturers of intermittent pneumatic compression are very helpful with the acquisition, sleeve sizing, home delivery and operating instructions. Patients would use venous pumps for one to two hours a day. These venous pumps have preset and prescribed graduated intermittent compression.

Anecdotally, we have had success with intermittent pneumatic compression to lessen the recurrence of venous ulceration in morbidly obese patients who are ambulatory, live alone and are unable to don compression garments due to mobility challenges. Collaboration with the patient’s medical team and ensuring a thorough cardiopulmonary assessment prior to initiation are important to ensure cardiac stability and avoid decompensation from an increased preload.34

Key Points To Consider With Compression Stockings

Once venous ulcers heal, one needs to consider the use of maintenance therapy to prevent recurrence. Clinicians should have patients wear some type of daily compression garment or device. Graduated compression stockings are one option and come in knee-high and thigh-high stockings. Slip-on inelastic devices with adjustable Velcro straps are also options.

Clinicians should place initial orders for compression socks prior to ulcer closure as many insurance companies will not pay for compression hose if no active ulcer exists. If the patient has lower leg edema, a compression bandage may initially be needed for edema reduction prior to sock measurement. Measurement is simple but essential. It usually consists of measuring the lower leg length and calf and ankle circumference. Customized fit stockings may be necessary for some patients. Some medical supply stores have a compression specialist on staff. However, this service seems to be less frequently available. Prescriptions for compression stockings from medical supply stores should include not only compression strength but patient measurements as well.

One would prescribe compression strength according to the severity of disease. Graduated compression of 30 to 40 mmHg at the ankle is recommended for chronic venous insufficiency and prevention of ulcer recurrence. It is important to mention that current stocking classifications are not standardized. In other words, a “class II” sock may represent 20 to 30 mmHg for one manufacturing company and 30 to 40 mmHg for another. Labels such as mild, moderate, firm and strong may also represent different strengths between companies.

Many insurance agencies will only pay for 30 to 40 mmHg stockings. Since compression hose needs to be replaced at least yearly, if not every three to six months, the patient cost can be high, especially when the socks are not reimbursed. Patients are often tempted to look for cheaper alternatives via mail order or online catalogues. However, one must encourage patients to be cautious regarding these entities as compression gradients may not be validated or even specified, there may be fewer options in size available, and the quality of the material may not be as durable. Reputable medical supply companies will take orders, bill insurances and deliver to the patient. Most will provide doctors’ offices with special order forms to facilitate the process.

Several companies make two-layer compression socks with the two layers intended to be worn together to achieve the prescribed compression. Many patients find the two layer systems easier to apply than the single layer socks. When using compression stockings, patients should receive instruction that it is best to shower in the evening and then don their socks first thing in the morning before edema has a chance to accumulate in the limb. It is important to emphasize to patients that “first thing in the morning” means before getting out of bed, not after breakfast or the morning news.

Clinicians may employ compression stockings for the treatment of smaller ulcers with manageable drainage instead of multi-layer bandages. Dual layer socks are often less disruptive over an ulcer dressing.36

One of the factors contributing to poor stocking compliance is application difficulty. Venous ulcer prevalence increases with age. Compounding this situation are the realities that comorbidities of musculoskeletal problems, neurological problems, fragility and lack of significant other assistance also increase with age.5 Although assistive donning devices are available, they are generally not covered by insurance carriers. Having a clinic assortment of application aids can help determine which would be most helpful.

Anti-embolic stockings are not appropriate for treating chronic venous disease. These stockings are made for patients who are non-ambulatory, non-mobile or bedridden to prevent venous thrombus. They have a very low graduated compression, typically only 8 to 18 mmHg, which cannot overcome the high pressures associated with ambulatory venous hypertension.37 They are not intended for long-term use and lose their elasticity over a couple of weeks.

Other Considerations To Keep In Mind

Venous insufficiency is very common and is the most likely cause of lower extremity edema.38 However, it is imperative to consider other causes of edema, especially in a population with multiple significant comorbidities.39,40 Prior to initiating compression therapy, one must ensure adequate arterial circulation. Studies have shown that up to 30 percent of people with lower extremity ulceration have concomitant peripheral arterial disease.41

Physical assessment including an ABI is often indicated. An ABI > 1.3 suggests poorly compressible vessels and an arterial Doppler with segmental and toe waveforms/pressures may be necessary.42 Most experts agree that an ABI 16,35,43 Patients with ABI readings between 0.5 and 0.8 may benefit from modified bandaging that offers a reduced compression of 15 to 25 mmHg.44

One must tailor compression therapy to the patient. Due to the initial discomfort that may occur with compression therapy, it may be necessary to begin with less compression and gradually increase to the indicated pressure. Patients who have a negative first experience with compression may be less willing to continue the treatment.35

Multiple factors have been implicated as contributing to poor therapy adherence.45 One of the inconveniences with compression bandages is the necessity to keep the dressing dry. There are devices that one can slip on over the leg to seal from the shower water. However, application may be difficult in patients with poor dexterity, strength or balance. Many patients are creative with large garbage bags.

Addressing this issue at the initiation of therapy will assist with maintaining a safe environment for the patient. Once therapy is established and progressing, it may be possible to coordinate visits with the patient and have them remove the bandage and shower prior to the visit. If there is assistance in the home, the patient might use short stretch bandages and one can teach the family how to remove and reapply these bandages safely after bathing. Remember to validate competence prior to allowing unsupervised application.

One should initiate patient education regarding the necessity for compression — both for ulcer treatment and for lifelong maintenance — at the first visit. An understanding of the pathophysiology of the disease helps with therapy adherence.46 However, ulcer recurrence is often associated with failure to wear the compression socks or use the venous pump as directed. Continued reinforcement at every visit is essential.

In Conclusion

Podiatrists frequently encounter venous ulcerations and chronic venous insufficiency in the clinical setting. The standard of care for management includes graduated compression therapy. It is important to rule out other potential causes of lower extremity edema and ensure vascular adequacy prior to the initiation of therapy. One should also consider the individual needs of each patient prior to choosing a compression plan of care.

Ms. Rivera is an instructor at the Dr. William M. Scholl College of Podiatric Medicine at Rosalind Franklin University of Medicine and Science in Chicago. She is also a nurse practitioner with a specialty in wound and foot care at the Center for Lower Extremity Ambulatory Research (CLEAR).

Dr. Wu is the Director of the aforementioned CLEAR at the Scholl College of Podiatric Medicine. She is an Associate Professor for the Center for Stem Cell and Regenerative Medicine at the School of Graduate and Postdoctoral Studies at the Rosalind Franklin University of Medicine and Science. Dr. Wu is also an Associate Professor in the Surgery Department and the Associate Dean of Research at the aforementioned Scholl College of Podiatric Medicine.

For further reading, see “Keys To Effective Wound Dressing Selection” in the August 2011 issue of Podiatry Today, “Key Insights On Treating Chronic Venous Ulcers” in the September 2008 issue or “Managing Venous Ulcers In The Lower Extremity” in the May 2004 issue.

Comments

As a disclosure, I am VP of Farrow Medical, which manufactures short stretch garments. This is a long comment.

I would like to clarify a point with regard to the definitions herein of inelastic versus short stretch, which I believe, as stated, allow for confusion, even historically, predating 2006.

I don't believe inelastic products are historically considered to be products with 30 to 70% stretch. In fact, Foldi specifically distinguishes between short stretch and inelastic.

Why would they be separated in textbooks and yet be referred to by others as the same or similar?

If a product with less than 15% stretch, as an example, is applied, there are several issues.
1. You are not really sure how much compression is being applied because the amount of compression is directly related to how hard the provider is pulling. Does the provider know how hard he is he is pulling? Does the next person applying know how hard he or she is pulling?
2. Products with this amount of stretch don't work terribly well over joints, such as the anterior ankle, and this can cause ulcerations.
3. True inelastic products are generally reserved in wound centers for patients with a low AB index, and they are applied with very little tension, meaning they are applying little if any significant resting compression. They depend upon a higher working compression to reduce/control edema.
4. If the leg decreases significantly in circumference as a result of higher working compression levels generated, the garment can slide down and the higher working compression advantage would be lost until readjusted.

"Short stretch" products are applied with some stretch and hence, inherent in that stretch is some tension, which translates into ~some~ compression. As the authors appropriately state, this compression level can fall of rather abruptly with time. Short stretch bandages, traditionally, are manufactured of 100% cotton and depend a good degree on the weave of the product to produce the tension and hence compression. So if a product which has some stretch but little sustained elastic compression of its own is applied near its maximal stretch, it would essentially function as inelastic, although if the leg reduced in size, it "might" shrink along with the leg, but also provide a lower working compression level.

If, however, a product with short (limited or low) stretch AND elastic fibers was used, the compression would not fall off as quickly and the performance would be hybridized with other elastic compression garments. By hybridized, I mean provide a steady lower resting compression (like a stocking) AND a higher working compression (more like inelastic).

Why is this important?

In my opinion, with elastic short stretch products ...
1. The short stretch can better cue you in to the amount of tension being applied by feeling the abruptness of the short stretch and hence the tension level.
2. The stretch allows for better functionality over joints.
3. The short stretch generally allows for more consistent low resting compression and higher working compression levels (working like a pump when the patient ambulates when properly applied). (It is sometimes referred to as a poor man's pump.)
4. The product can shrink some if the leg decreases in size, limiting slippage and the need for adjustments.

As a clinical example, in a chair-bound nursing home resident, a truly inelastic product that is properly applied might apply very little resting compression (or if too tight could be a tourniquet). A short stretch product with elastic fibers would apply some sustained resting compression with the potential for higher working compression when properly applied. Long stretch wraps have the potential to produce highest sustained resting compressions, which can be a little more hazardous if not professionally applied, and lower working compressions unless applied with a significant (potentially more dangerous) amount of tension.

Conversely, if a patient had poor arterial circulation, the provider may opt to apply a product that is "inelastic" with very little tension applied because a lower resting compression has a lower potential to block arterial circulation, but still has the potential to provide a higher working compression to help reduce/control edema. Note that this would work best if the calf muscle pump was functional.

One last point. A product that is inelastic applied and just barely snug would apply a low resting compression when vertical, but very little, if any, when lying down. Short stretch would apply more resting compression than inelastic when lying down. Long stretch would generally provide the most compression when lying down (and the least potential for high working compression when vertical). So patients with impaired arterial circulation are generally safer with inelastic, then short stretch products, when they lie down, as opposed to long stretch, IF compression is safe be applied at all depending on the situation.